Update on type 2 diabetes as a cardiovascular disease risk equivalent

United States Pooled Cohort Cardiovascular Disease Risk Scores in Adults With Diabetes Mellitus

Background

There is significant heterogeneity in cardiovascular disease (CVD) risk among patients with diabetes mellitus (DM).

Objectives

The purpose of this study was to develop risk scores for total CVD and its components from a contemporary pooled, observational cohort of U.S. adults with DM.

Methods

CVD-free adults with DM aged 40 to 79 years were pooled from 4 U.S. population-based cohorts (CARDIA [Coronary Artery Risk Development in Young Adults], Framingham Offspring, Jackson Heart Study, and the MESA (Multiethnic Study of Atherosclerosis) studied since 2000. Baseline DM-specific and non-DM-specific CVD risk factors were evaluated as predictors. We developed 10-year DM Risk Scores (DMRS) for total CVD, atherosclerotic CVD (ASCVD), coronary heart disease (CHD), heart failure (HF) and stroke. Score performance was validated internally and externally.

Results

We included 2,174 adults with DM mean age 59.2 ± 10.5 years, 55.4% female and 47.5% Black followed up to 10 years. Age, sex, HbA1c, creatinine, systolic blood pressure, DM medication, and smoking were the most important predictors. The DMRS had good internal discrimination (c-statistics 0.72, 0.72, 0.72, 0.79 and 0.73 for CVD, ASCVD, CHD, HF, and stroke) and calibration (calibration slopes 0.93, 0.95, 0.93, 0.98, and 0.89 for CVD, ASCVD, CHD, HF, and stroke; Greenwood Nam-D'Agostino calibration tests were significant for CHD (P < 0.01) and CVD (P < 0.05) but not for ASCVD, HF, and stroke). From external validation in 2 other cohorts, the DMRS outperformed current risk scores.

Conclusions

Our U.S. pooled cohort DMRS for predicting CVD events demonstrated good predictive performance for assessing CVD risk in adults with DM.

Association of cardiovascular health score trajectory and risk of subsequent cardiovascular disease in non-diabetic population: a cohort study

BACKGROUND

Diabetes is an important risk factor for cardiovascular disease (CVD), but in the non-diabetic population, high glucose values within the normal range are also positively associated with CVD risk. There is a lack of concern for people without diabetes and evidence is lacking regarding the association between changes in cardiovascular health score (CVHS) and CVD risk in the non-diabetic population.

METHODS

The current study included 37,970 non-diabetic participants free of CVD events in or before 2010 from the Kailuan Study and calculated CVHS according to the overall status of 7 cardiovascular health metrics between the 2006 and 2010 waves. Latent mixture models were used to explore the subgroups with different development trends included in the context of the Kailuan non-diabetic population and to identify the trajectory of each subgroup. The outcomes of the current study were CVD events, including myocardial infarction and stroke. CVHS trajectory was developed to predict subsequent CVD risk from 2010 to 2020. The Cox proportional hazard model was established to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of CVD across different trajectory patterns.

RESULTS

Five distinct CVHS trajectory patterns were identified, including low-stable pattern (n = 2835), moderate-increasing pattern (n = 3492), moderate-decreasing pattern (n = 7526), high-stable I pattern (n = 17,135), and high-stable II pattern (n = 6982). Compared with the low-stable pattern, participants with the high-stable II pattern had a lower subsequent risk of CVD (HR = 0.22, 95%CI = 0.18-0.28); In stratification analysis, the lower risk for CVD was observed in females (HR = 0.10, 95%CI = 0.05-0.23, P for interaction < 0.05) and those aged < 60 years (HR = 0.16, 95%CI = 0.11 to 0.22, P for interaction < 0.05).

CONCLUSIONS

CVHS trajectory patterns were associated with an altered CVD risk in the non-diabetic population. When stratified by age and sex, the association was stronger in young adults and females.

The relationship of low-density lipoprotein cholesterol and all-cause or cardiovascular mortality in patients with type 2 diabetes: a retrospective study

Background

The optimal levels of low-density lipoprotein cholesterol (LDL-C) in patients with type 2 diabetes (T2D) are not currently clear. In this study, we determined the relationship between various mean LDL-C and all-cause or cardiovascular mortality risks in patients with T2D, stratifying by albumin level, age, sex, and antilipid medication use. We also evaluated the association of LDL-C standard deviation (LDL-C-SD) and all-cause and cardiovascular mortality by type of antilipid medication use.

Methods

A total of 46,675 T2D patients with a prescription for antidiabetic agents >6 months from outpatient visits (2003-2018) were linked to Taiwan's National Death Registry to identify all-cause and cardiovascular mortality. The Poisson assumption was used to estimate mortality rates, and the Cox proportional hazard regression model was used to assess the relative hazards of respective mortality in relation to mean LDL-C in patient cohorts by albumin level, age, sex, and antilipid use adjusting for medications, comorbidities, and laboratory results. We also determined the overall, and anti-lipid-specific mortality rates and relative hazards of all-cause and cardiovascular mortality associated with LDL-C-SD using the Poisson assumption and Cox proportional hazard regression model, respectively.

Results

All-cause and cardiovascular mortality rates were the lowest in T2D patients with a mean LDL-C > 90-103.59 mg/dL in the normal albumin group (≥ 3.5 g/dL). Compared to T2D patients with a mean LDL-C > 90-103.59 mg/dL, those with a mean LDL-C ≤ 77 mg/dL had an elevated risk of all-cause mortality in both the normal and lower albumin groups. T2D patients with a mean LDL-C ≤ 90 and > 103.59-119 mg/dL had relatively higher risk of cardiovascular mortality in the normal albumin group, but in the lower albumin group (<3.5 g/dL), any level of mean LDL-C ≤ 119 mg/dL was not significantly associated with cardiovascular mortality. Increased risks of all-cause and cardiovascular mortality were observed in patients with a mean LDL-C ≤ 77 mg/dL in both sexes and in all age groups except in those aged <50 years, a lower mean LDL-C was not associated with cardiovascular mortality. Similarly, patients with an LDL-C-SD <10^th and > 90^th percentiles were associated with significant risks of all-cause and cardiovascular mortality. In statin users, but not fibrate users, lower and higher levels of mean LDL-C and LDL-C-SD were both associated with elevated risks of all-cause and cardiovascular mortality.

Conclusions

The optimal level of LDL-C was found to be >90-103.59 mg/dL in T2D patients. Lower and higher levels of mean LDL-C and LDL-C-SD were associated with all-cause and cardiovascular mortality, revealing U-shaped associations. Further studies are necessary to validate the relationship between optimal LDL-C levels and all-cause and cardiovascular mortality in patients with diabetes.

Relationship between Indices of Vascular Function and Presence of Overt Cardiovascular Disease among Persons with Poorly Controlled Type 2 Diabetes

The aim of this study was to assess the factors associated with impaired vascular function in patients with poorly controlled type 2 diabetes (DM2) with and without overt cardiovascular disease (CVD). Ninety-five patients with DM2 and poor glycemic control were recruited and divided into two groups: Group 1, with known CVD (n = 38), and Group 2, without CVD (n = 57). Patients in Group 2 were further subdivided into those with short (<5 years, group 2b) and long (>5 years, group 2a) diabetes duration. Subclinical markers of atherosclerosis were assessed. Glycemic control was similar in the two groups (HbA1c: 9.2% (1.5) vs. 9.4% (1.8), p = 0.44). In Group 1, lower FMD (3.13 (2.16)% vs. 4.7 (3.4)%, p < 0.05) and higher cIMT (1.09 (0.3) mm vs. 0.96 (0.2) mm, p < 0.05) was seen compared with Group 2, whereas PWV was similar (12.1 (3.4) vs. 11.3 (3.0) m/s, p = 0.10). Patients in Group 2b had significantly lower PWV and cIMT and higher FMD compared to Group 1 (p < 0.05). Among patients with poorly controlled T2D, more pronounced vascular dysfunction was present in those with overt macrovascular disease. In patients with T2D without known CVD, vascular dysfunction was associated with disease duration. The use of vascular indices for cardiovascular risk stratification in patients with T2D requires further study.

Identification and Predictors for Cardiovascular Disease Risk Equivalents among Adults With Diabetes Mellitus

OBJECTIVE

We examined diabetes mellitus (DM) as a cardiovascular disease (CVD) risk equivalent based on diabetes severity and other CVD risk factors.

RESEARCH DESIGN AND METHODS

We pooled 4 US cohorts (ARIC, JHS, MESA, FHS-Offspring) and classified subjects by baseline DM/CVD. CVD risks between DM+/CVD- vs. DM-/CVD+ were examined by diabetes severity and in subgroups of other CVD risk factors. We developed an algorithm to identify subjects with CVD risk equivalent diabetes by comparing the relative CVD risk of being DM+/CVD- vs. DM-/CVD+.

RESULTS

The pooled cohort included 27,730 subjects (mean age of 58.5 years, 44.6% male). CVD rates per 1000 person-years were 16.5, 33.4, 43.2 and 71.4 among those with DM-/CVD-, DM+/CVD-, DM-/CVD+ and DM+/CVD+, respectively. Compared with those with DM-/CVD+, CVD risks were similar or higher for those with HbA1c ≥ 7%, diabetes duration ≥10 years, or diabetes medication use while those with less severe diabetes had lower risks. Hazard ratios (95%CI) for DM+/CVD- vs. DM-/CVD+ were 0.96(0.86-1.07), 0.97(0.88-1.07), 0.96(0.82-1.13), 1.18(0.98-1.41), 0.93(0.85-1.02) and 1.00(0.89-1.13) among women, white race, age <55 years, triglycerides ≥2.26 mmol/L, hs-CRP ≥ 2 mg/L and eGFR<60 mL/min/1.73m2, respectively. In DM+/CVD- group, 19.1% had CVD risk equivalent diabetes with a lower risk score but a higher observed CVD risk.

CONCLUSION

Diabetes is a CVD risk equivalent in one-fifth of CVD-free adults living with diabetes. High HbA1c, long diabetes duration, and diabetes medication use were predictors of CVD risk equivalence. Diabetes is a CVD risk equivalent for women, white people, those of younger age, with higher triglycerides or CRP, or reduced kidney function.

Pyridostigmine regulates glucose metabolism and mitochondrial homeostasis to reduce myocardial vulnerability to injury in diabetic mice

Diabetic patients are more susceptible to myocardial ischemia damage than nondiabetic patients, with worse clinical outcomes and greater mortality. The mechanism may be related to glucose metabolism, mitochondrial homeostasis, and oxidative stress. Pyridostigmine may improve vagal activity to protect cardiac function in cardiovascular diseases. Researchers have not determined whether pyridostigmine regulates glucose metabolism and mitochondrial homeostasis to reduce myocardial vulnerability to injury in diabetic mice. In the present study, autonomic imbalance, myocardial damage, mitochondrial dysfunction, and oxidative stress were exacerbated in isoproterenol-stimulated diabetic mice, revealing the myocardial vulnerability of diabetic mice to injury compared with mice with diabetes or exposed to isoproterenol alone. Compared with normal mice, the expression of glucose transporters (GLUT)1/4 phosphofructokinase (PFK) FB3, and pyruvate kinase isoform (PKM) was decreased in diabetic mice, but increased in isoproterenol-stimulated normal mice. Following exposure to isoproterenol, the expression of (GLUT)1/4 phosphofructokinase (PFK) FB3, and PKM decreased in diabetic mice compared with normal mice. The downregulation of SIRT3/AMPK and IRS-1/Akt in isoproterenol-stimulated diabetic mice was exacerbated compared with that in diabetic mice or isoproterenol-stimulated normal mice. Pyridostigmine improved vagus activity, increased GLUT1/4, PFKFB3, and PKM expression, and ameliorated mitochondrial dysfunction and oxidative stress to reduce myocardial damage in isoproterenol-stimulated diabetic mice. Based on these results, it was found that pyridostigmine may reduce myocardial vulnerability to injury via the SIRT3/AMPK and IRS-1/Akt pathways in diabetic mice with isoproterenol-induced myocardial damage. This study may provide a potential therapeutic target for myocardial damage in diabetic patients.

CCAAT/enhancer binding protein homologous protein knockdown alleviates hypoxia-induced myocardial injury in rat cardiomyocytes exposed to high glucose

Diabetic patients are more sensitive to ischemic injury than non-diabetics. Endoplasmic reticulum (ER) stress has been reported to be closely associated with the pathophysiology of ischemic injury in diabetes. The aim of the present study was to investigate the mechanisms involved in the progression of diabetes complicated by myocardial infarction (MI) and further verify the role of CCAAT/enhancer binding protein (C/EBP)-homologous protein (CHOP) using an in vitro model of diabetes/MI. The rats were exposed to 65 mg/kg streptozotocin (STZ) and left anterior descending (LAD) coronary artery ligation. ST-segment elevation, heart rate, left ventricular systolic pressure (LVSP) and LV end-diastolic pressure (LVEDP) were measured. Serum creatinine kinase-MB (CK-MB) and cardiac troponin T (cTnT) levels were examined by ELISA. Infarct size and apoptosis were measured by triphenyltetrazolium chloride staining and terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling assay. Pathological changes were evaluated by hematoxylin and eosin staining. H9c2 cells were used to establish an in vitro model of diabetes complicated by MI. Following CHOP knockdown, cell viability, cell cycle distribution and apoptosis were examined by Cell Counting Kit-8 assay, flow cytometry and Hoechst staining. Glucose-regulated protein 78 (GRP78), CHOP, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), endoplasmic reticulum oxidoreductase 1 (Ero1)-α, Ero1β and protein disulfide isomerase (PDI) levels in both myocardial tissues and H9c2 cells were determined by western blotting. In the present study, diabetes complicated by MI promoted ST-segment elevation and myocardial apoptosis, increased infarct size, induced pathological changes and elevated LVEDP, CK-MB, cTnT, GRP78, CHOP, Bax, Ero1α, Ero1β and PDI; however, it decreased heart rate, LVSP and Bcl-2. Additionally, high glucose combined with hypoxic treatment reduced cell viability, induced cell cycle arrest at G1 phase, promoted cell apoptosis, and activated the GRP78/CHOP and Ero1/PDI signaling pathways, which were reversed by CHOP knockdown. Thus, CHOP may be an effective therapeutic target for the treatment of diabetes complicated by MI.

Safety and efficacy of liraglutide treatment in Japanese type 2 diabetes patients after acute myocardial infarction: A non-randomized interventional pilot trial

BACKGROUND

Glucagon-like peptide 1 analogs are expected to exert a cardio-protective action due to their effective glucose-lowering action and favorable potency on multifactorial metabolic pathways. However, the safety and tolerability of liraglutide treatment after a recent acute coronary syndrome (ACS) in Japanese patients with type 2 diabetes mellitus (T2DM) have yet to be fully established.

METHODS

A total of eight T2DM patients were recruited within 2 weeks after the onset of a ST-elevation myocardial infarction (STEMI) followed by successful percutaneous coronary intervention (PCI). The patients continued to receive liraglutide (up to 0.9mg once daily) for 24 weeks after the ACS combined with standard treatment such as a statin or beta-blocker. Changes in various metabolic parameters from pre-liraglutide treatment values were evaluated 24 weeks after liraglutide treatment, and included glycemic and lipid profiles, and cardiac systolic and diastolic function assessed by cardiac ultrasonography.

RESULTS

Twenty-four weeks of treatment with liraglutide reduced body weight (67.0±5.8kg to 62.0±7.8kg, p=0.003) and HbA1c level (6.6±0.5% to 5.9±0.5%, p=0.006) and increased the level of 1,5-anhydroglucitol (12.8±6.9μg/mL to 18.7±8.2μg/mL, p=0.008) without development of hypoglycemia. There were no significant changes over 24 weeks in left ventricular systolic or diastolic function assessed by cardiac ultrasonography. No participant developed a major adverse cardiac event during the 24 weeks of liraglutide treatment, defined as cardiac death, new onset or recurrence of myocardial infarction, or needing target lesion revascularization.

CONCLUSIONS

The present trial demonstrated that liraglutide treatment after onset of STEMI was well-tolerated in Japanese patients with T2DM over 24 weeks, and provided the first evidence to support clinical application of liraglutide treatment even just after ACS in Japanese high-risk T2DM patients.

Diabetes screening intervals based on risk stratification

BACKGROUND

Guidelines for frequency of Type 2 diabetes mellitus (DM) screening remain unclear, with proposed screening intervals typically based on expert opinion. This study aims to demonstrate that HbA1c screening intervals may differ substantially when considering individual risk for diabetes.

METHODS

This was a multi-institutional retrospective open cohort study. Data were collected between April 1999 to March 2014 from one urban and one rural cohort in Japan. After categorization by age, we stratified individuals based on cardiovascular disease risk (Framingham 10-year cardiovascular risk score) and body mass index (BMI). We adapted a signal-to-noise method for distinguishing true HbA1c change from measurement error by constructing a linear random effect model to calculate signal and noise of HbA1c. Screening interval for HbA1c was defined as informative when the signal-to-noise ratio exceeded 1.

RESULTS

Among 96,456 healthy adults, 46,284 (48.0%) were male; age (range) and mean HbA1c (SD) were 48 (30-74) years old and 5.4 (0.4)%, respectively. As risk increased among those 30-44 years old, HbA1c screening intervals for detecting Type 2 DM consistently decreased: from 10.5 (BMI <18.5) to 2.4 (BMI > 30) years, and from 8.0 (Framingham Risk Score <10%) to 2.0 (Framingham Risk Score ≥20%) years. This trend was consistent in other age and risk groups as well; among obese 30-44 year olds, we found substantially shorter intervals compared to other groups.

CONCLUSION

HbA1c screening intervals for identification of DM vary substantially by risk factors. Risk stratification should be applied when deciding an optimal HbA1c screening interval in the general population to minimize overdiagnosis and overtreatment.

Rationale and design of a multicenter randomized controlled study to evaluate the preventive effect of ipragliflozin on carotid atherosclerosis: the PROTECT study

BACKGROUND

Type 2 diabetes mellitus is associated strongly with an increased risk of micro- and macro-vascular complications, leading to impaired quality of life and shortened life expectancy. In addition to appropriate glycemic control, multi-factorial intervention for a wide range of risk factors, such as hypertension and dyslipidemia, is crucial for management of diabetes. A recent cardiovascular outcome trial in diabetes patients with higher cardiovascular risk demonstrated that a SGLT2 inhibitor markedly reduced mortality, but not macro-vascular events. However, to date there is no clinical evidence regarding the therapeutic effects of SGLT2 inhibitors on arteriosclerosis. The ongoing PROTECT trial was designed to assess whether the SGLT2 inhibitors, ipragliflozin, prevented progression of carotid intima-media thickness in Japanese patients with type 2 diabetes mellitus.

METHODS

A total of 480 participants with type 2 diabetes mellitus with a HbA1c between 6 and 10 % despite receiving diet/exercise therapy and/or standard anti-diabetic agents for at least 3 months, will be randomized systematically (1:1) into either ipragliflozin or control (continuation of conventional therapy) groups. After randomization, ipragliflozin (50-100 mg once daily) will be added on to the background therapy in participants assigned to the ipragliflozin group. The primary endpoint of the study is the change in mean intima-media thickness of the common carotid artery from baseline to 24 months. Images of carotid intima-media thickness will be analyzed at a central core laboratory in a blinded manner. The key secondary endpoints include the change from baseline in other parameters of carotid intima-media thickness, various metabolic parameters, and renal function. Other cardiovascular functional tests are also planned for several sub-studies.

DISCUSSION

The PROTECT study is the first to assess the preventive effect of ipragliflozin on progression of carotid atherosclerosis using carotid intima-media thickness as a surrogate marker. The study has potential to clarify the protective effects of ipragliflozin on atherosclerosis. Trial registration Unique Trial Number, JPRN/UMIN000018440 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000021348 ).

Myocardial dysfunction and cardiovascular disease in type 2 diabetes

Type 2 diabetes mellitus (T2DM) is strongly associated with increased risk of myocardial dysfunction and cardiovascular disease (CVD), two separate conditions which often co-exist and influence each other's course. The prevalence of myocardial dysfunction may be as high as 75% in T2DM populations but is often overlooked due to the initial asymptomatic nature of the disease, complicating co-morbidities such as coronary artery disease (CAD) and obesity, and the lack of consensus on diagnostic criteria. More sensitive echocardiographic applications are furthermore needed to improve detection of early subclinical changes in myocardial function which do not affect conventional echocardiographic parameters. The pathophysiology of the diabetic myocardial dysfunction is not fully elucidated, but involves hyperglycemia and high levels of free fatty acids. It evolves over several years and increases the risk of developing overt HF, and is suggested to at least in part account for the worse outcome seen in T2DM individuals after cardiac events. CAD and stroke are the most frequent CV manifestations among T2DM patients and relate to a large degree to the accelerated atherosclerosis driven by inflammation. Diagnosing CAD is challenging due to the lower sensitivity inherent in the diagnostic tests and there is thus a need for new biomarkers to improve prediction and detection of CAD. It seems that a multi-factorial approach (i.e. targeting several CV risk factors simultaneously) is superior to a strict glucose lowering strategy in reducing risk for macrovascular events, and recent research may even support an effect also on HF outcomes.

SIRT1 protects against myocardial ischemia-reperfusion injury via activating eNOS in diabetic rats

Background

Diabetic patients are more sensitive to myocardial ischemic injury than non-diabetic patients. Silent information regulator 1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent histone deacetylase making the heart more resistant to ischemic injury. As SIRT1 expression is considered to be reduced in diabetic heart, we therefore hypothesized that up-regulation of SIRT1 in the diabetic heart may overcome its increased susceptibility to ischemic injury.

Methods

Male Sprague–Dawley rats were fed with high-fat diet and injected with streptozotocin once to induce diabetes. Diabetic rats received injections of adenoviral vectors encoding SIRT1 (Ad-SIRT1) at five myocardial sites. Four days after adenoviral injection, the rats were subjected to myocardial ischemia and reperfusion (MI/R). Outcome measures included left ventricular function, infarct size, cellular death and oxidative stress.

Results

Delivery of Ad-SIRT1 into the hearts of diabetic rats markedly increased SIRT1 expression. Up-regulation of SIRT1 in diabetic hearts improved cardiac function and reduced infarct size to the extent as in non-diabetic animals following MI/R, which was associated with reduced serum creatine kinase-MB, lactate dehydrogenase activities and cardiomyocyte apoptosis. Moreover, Ad-SIRT1 reduced the increase in the superoxide generation and malonaldialdehyde content and simultaneously increased the antioxidant capability. Furthermore, Ad-SIRT1 increased eNOS phosphorylation and reduced eNOS acetylation in diabetic hearts. NOS inhibitor L-NAME inhibited SIRT1-enhanced eNOS phosphorylation, and blunted SIRT1-mediated anti-apoptotic and anti-oxidative effects and cardioprotection.

Conclusions

Overexpression of SIRT1 reduces diabetes-exacerbated MI/R injury and oxidative stress via activating eNOS in diabetic rats. The findings suggest SIRT1 may be a promising novel therapeutic target for diabetic cardiac complications.

Quantifying cardiovascular disease risk factors in patients with psoriasis: a meta-analysis

BACKGROUND

In a previous meta-analysis on categorical data we found an association between psoriasis and cardiovascular disease and associated risk factors.

OBJECTIVES

To quantify the level of cardiovascular disease risk factors in order to provide additional data for the clinical management of the increased risk.

METHODS

This was a meta-analysis of observational studies with continuous outcome using random-effects statistics. A systematic search of studies published before 25 October 2012 was conducted using the databases Medline, EMBASE, International Pharmaceutical Abstracts, PASCAL and BIOSIS.

RESULTS

We included 59 studies with up to 18 666 cases and 50 724 controls. Psoriasis cases had a higher total cholesterol [weighted mean difference 8·83 mg dL(-1) , 95% confidence interval (CI) 2·94-14·72, P = 0·003 (= 0·23 mmol L(-1) )], higher low-density lipoprotein cholesterol [9·90 mg dL(-1) , 95% CI 1·56-18·20, P = 0·020 (= 0·25 mmol L(-1) )], higher triglyceride [16·32 mg dL(-1) , 95% CI 12·02-20·63, P < 0·001 (= 0·18 mmol L(-1) )], a higher systolic blood pressure (4·77 mmHg, 95% CI 1·62-7·92, P = 0·003), a higher diastolic blood pressure (2·99 mmHg, 95% CI 0·60-5·38, P = 0·014), higher body mass idex (0·73 kg m(-2) , 95% CI 0·37-1·09, P < 0·001), higher waist circumference (3·61 cm, 95% CI 2·12-5·10, P < 0·001), higher fasting glucose [3·52 mg dL(-1) , 95% CI 0·64-6·41, P = 0·017 (= 0·20 mmol L(-1) )], higher nonfasting glucose [11·70 mg dL(-1) , 95% CI 11·24-12·15, P < 0·001 (= 0·65 mmol L(-1) )] and a higher HbA1c [1·09 mmol mol(-1) , 95% CI 0·87-1·31, P < 0·001 (= 2·2%)].

CONCLUSIONS

From a preventive medicine perspective, the weighted mean differences between cases and controls are significant, and therefore relevant to the clinical management of patients with psoriasis.

Oscillating high glucose enhances oxidative stress and apoptosis in human coronary artery endothelial cells

PURPOSE

To investigate the toxic effect of oscillating high glucose (OHG) versus persistent high glucose (PHG) in inducing oxidative stress and cellular apoptosis in human coronary artery endothelial cells (HCAECs) in vitro.

METHODS

HCAECs were incubated for 72 h continuously in normal glucose (5.5 mmol/L glucose), PHG (25 mmol/L glucose), OHG (5.5 mmol and 25 glucose mmol/L alternating every 6 h) and mannitol, respectively. Cellular viability, concentration of oxidative stress biomarkers (MDA and GSH) in the supernatants of cell culture, and intracellular ROS level were quantitated after exposure to different concentrations of glucose for a total 72 h. Apoptosis of HCAECs cultured with various glucose levels was evaluated by annexin V-FITC and PI staining followed by analysis with flow cytometry. The expressions of HO-1 and Nrf2 were measured by RT-qPCR and Western blotting at the end of the experiment.

RESULTS

HCAECs cultured with PHG showed decreased cellular viability compared to those with normal level of glucose (p < 0.05). The decrease was more pronounced under OHG condition (p < 0.05). Cellular oxidative stress was provoked in HCAECs exposed to PHG with marked increased MDA level, reduced GSH concentration and elevated ROS production (p < 0.05). The stress was further amplified in the setting of OHG (p < 0.05). The cellular apoptosis was enhanced by culturing with PHG, and to a greater extent when incubated with OHG. Both expressions of HO-1 and Nrf2 were suppressed in HCAECs in persistent hyperglycemia condition, while the inhibition was more intense in the fluctuating hyperglycemia condition (p < 0.05).

CONCLUSIONS

These findings indicate that OHG could be more detrimental to HCAECs than PHG. This is probably due to the enhancement of oxidative stress and cellular apoptosis induced by frequent glucose swings through the inhibition of Nrf2/HO-1 pathway.

Are statin trials in diabetes representative of real-world diabetes care: a population-based study on statin initiators in Finland

OBJECTIVE

To assess the representativeness of the Heart Protection Study (HPS) and the Collaborative Atorvastatin Diabetes Study (CARDS) for incident statin users.

DESIGN

A population-based analysis with linked register data.

SETTING

Finland.

POPULATION

56 963 patients with diabetes initiating statin use from 2005 to 2008.

MAIN OUTCOME MEASURES

We determined the proportions of real-world patients who fulfilled the eligibility criteria for HPS and CARDS trials and assessed the cardiovascular disease (CVD) event rates, assumed to reflect the background CVD risk, for those eligible and ineligible. We used descriptive statistics to identify the patient characteristics, lipid-lowering interventions and adherence to statin therapy.

RESULTS

Of the real-world patients, 57% (N=32 582) fulfilled the eligibility criteria for HPS (DM) and 49% (N=20 499) of those without CVD for CARDS. The patients ineligible for HPS (DM) had a higher cumulative risk for CVD events than those eligible, whereas regarding CARDS the cumulative risks were of similar magnitude. The overall CVD event rates seemed to be comparable to those in the reviewed trials. Both trials were under-representative of women and users of antihypertensive agents and metformin. 27% and 29% of real-world patients had an initial statin dose corresponding to <20 mg of simvastatin. The proportions of patients who were deemed adherent were 57% in the real world and 85% in both trials.

CONCLUSIONS

Only half of the real-world patients would have qualified for the HPS (DM) and CARDS, limiting their representativeness for clinical practice. Women and users of antihypertensive agents and metformin were under-represented in both trials. These deviations reflect the changes in diabetes treatment over the years and are not expected to modify the average treatment effects of statins on CVD. Prescribing of lower statin doses in clinical practice than used in the trials and lower adherence may, however, attenuate the benefits in the real world.

Insulin resistance and hyperglycaemia in cardiovascular disease development

The prevalence of diabetes mellitus will likely increase globally from 371 million individuals in 2013 to 552 million individuals in 2030. This epidemic is mainly attributable to type 2 diabetes mellitus (T2DM), which represents about 90-95% of all cases. Cardiovascular disease is the leading cause of mortality among individuals with diabetes mellitus, and >50% of patients will die from a cardiovascular event-especially coronary artery disease, but also stroke and peripheral vascular disease. Classic risk factors such as elevated levels of LDL cholesterol and blood pressure, as well as smoking, are risk factors for adverse cardiovascular events in patients with type 1 diabetes mellitus (T1DM) and T2DM to a similar degree as they are in healthy individuals. Patients with T1DM develop insulin resistance in the months after diabetes mellitus diagnosis, and patients with T2DM typically develop insulin resistance before hyperglycaemia occurs. Insulin resistance and hyperglycaemia, in turn, further increase the risk of adverse cardiovascular events. This Review discusses the mechanisms by which T1DM and T2DM can lead to cardiovascular disease and how these relate to the risk factors for coronary artery disease.

Resveratrol ameliorates diabetic vascular inflammation and macrophage infiltration in db/db mice by inhibiting the NF-κB pathway

In this study, resveratrol (RSV) - a potent sirtuin 1 activator - was found to have beneficial effects on glucolipid metabolism and improve inflammatory mediators and markers of oxidative stress. Diabetic (db/db) mice and non-diabetic C57BL/6J mice were used in the study. The db/db mice were treated with or without 0.3% RSV mixed with chow for 8 weeks. Dietary RSV significantly lowered blood glucose, plasma lipid and free fatty acid levels in db/db mice. RSV markedly inhibited the expression of intercellular adhesion molecule-1 (ICAM-1), endothelial vascular cell adhesion molecule-1 (VCAM-1) and monocyte chemoattractant protein-1 (MCP-1) in the aorta and the blood plasma of db/db mice (p < 0.05). Levels of mac-3-positive macrophages (measure of the infiltration of activated macrophages) were lower in RSV-treated diabetic mice than in their untreated counterparts (p < 0.05). RSV treatment reduced the activity of the transcriptional regulator nuclear factor kappa B (NF-κB) in aortic tissues (p < 0.05). Thus, RSV treatment reduced ICAM-1, VCAM-1 and MCP-1 expression in the aorta and ICAM-1, VCAM-1 and MCP-1 levels in the plasma of diabetic mice. Since dietary supplementation with RSV also reduced NF-κB activities in the aorta, the therapeutic effects of RSV might be associated with the downregulation of NF-κB.

Vitamin E-gene interactions in aging and inflammatory age-related diseases: implications for treatment. A systematic review

Aging is a complex biological phenomenon in which the deficiency of the nutritional state combined with the presence of chronic inflammation and oxidative stress contribute to the development of many age-related diseases. Under this profile, the free radicals produced by the oxidative stress lead to a damage of DNA, lipids and proteins with subsequent altered cellular homeostasis and integrity. In young-adult age, the cell has a complex efficient system to maintain a proper balance between the levels of free radicals and antioxidants ensuring the integrity of cellular components. In contrast, in old age this balance is poorly efficient compromising cellular homeostasis. Supplementation with Vitamin E can restore the balance and protect against the deteriorating effects of oxidative stress, progression of degenerative diseases, and aging. Experiments in cell cultures and in animals have clearly shown that Vitamin E has a pivotal role as antioxidant agent against the lipid peroxidation on cell membranes preserving the tissue cells from the oxidative damage. Such a role has been well documented in immune, endothelial, and brain cells from old animals describing how the Vitamin E works both at cytoplasmatic and nuclear levels with an influence on many genes related to the inflammatory/immune response. All these findings have supported a lot of clinical trials in old humans and in inflammatory age-related diseases with however contradictory and inconsistent results and even indicating a dangerous role of Vitamin E able to affect mortality. Various factors can contribute to all the discrepancies. Among them, the doses and the various isoforms of Vitamin E family (α,β,γ,δ tocopherols and the corresponding tocotrienols) used in different trials. However, the more plausible gap is the poor consideration of the Vitamin E-gene interactions that may open new roadmaps for a correct and personalized Vitamin E supplementation in aging and age-related diseases with satisfactory results in order to reach healthy aging and longevity. In this review, this peculiar nutrigenomic and/or nutrigenetic aspect is reported and discussed at the light of specific polymorphisms affecting the Vitamin E bioactivity.

Astilbin protects diabetic rat heart against ischemia-reperfusion injury via blockade of HMGB1-dependent NF-κB signaling pathway

Astilbin, a flavonoid compound was isolated from the rhizome of Smilax china L. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effect of Astilbin on diabetic rats in vivo and elucidated the potential mechanism in vitro. The results showed that Astilbin significantly attenuated hypoxia-induced cell injury in a concentration-dependent manner. Treatment of H9c2 cells with Astilbin at 15 μM blocked nuclear factor kappaB (NF-κB) phosphorylation by blocking High-mobility group box protein 1 (HMGB1) expression. Treatment of diabetic rats with Astilbin by intravenous injection (i.v.) at a single dose of 50 mg/kg protected the rats from myocardial I/R injury as indicated by decreasing infarct volume, improving hemodynamics and reducing myocardial damage, and also lowered serum levels of pro-inflammatory factors, reduced HMGB1 and phosphorylated NF-κB expression in ischemic myocardial tissue from diabetic rats. Additionally, treatment of diabetic rats with Astilbin at dose of 50 mg/kg by i.v. for continuous 14 days attenuated cardiac remodeling in the model myocardial I/R injury. These protective effects suggested that Astilbin might be due to block of the myocardial inflammatory cascade via the HMGB1-dependent NF-κB signaling pathway.

Resistant starch improves insulin resistance and reduces adipose tissue weight and CD11c expression in rat OLETF adipose tissue

OBJECTIVE

CD11s/CD18 dimers induce monocyte/macrophage infiltration into many tissues, including adipose tissues. In particular, it was reported that β2-integrin CD11c-positive macrophages in adipose tissues are closely associated with the development of insulin resistance. The aim of this study was to determine whether intake of resistant starch (RS) reduces macrophage accumulation in adipose tissues and inhibits the development of insulin resistance at an early stage in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

METHODS

Twenty-two-wk-old male OLETF rats were fed a control diet (55% α-corn starch) or an RS diet (55% RS) for 5 wk. An oral glucose tolerance test was performed after 4 wk of feeding; tissues (mesenteric and epididymal adipose tissues, and liver) and tail vein blood were collected after 5 wk of feeding the test diets.

RESULTS

Feeding the RS diet to OLETF rats for 5 wk improved insulin resistance, reduced the mesenteric adipose tissue weight, and enhanced the number of small adipocytes. CD68 expression, a macrophage infiltration marker, was not changed by the RS diet, whereas the gene expression levels of integrins such as CD11c, CD11d, and CD18, but not CD11a, and CD11b, were significantly reduced. CD11c protein expression was reduced by the RS diet.

CONCLUSION

These findings suggest that part of the mechanism for the improved insulin resistance by the RS diet involves a reduction of CD11c expression in adipose tissues.

Chronic Mild Hyperglycemia in GCK-MODY Patients Does Not Increase Carotid Intima-Media Thickness

Aim. GCK-MODY is an autosomal dominant form of diabetes caused by heterozygous mutations in the glucokinase gene leading to a lifelong mild hyperglycemia. The risk of macrovascular complications is considered low, but studies are limited. We, therefore, investigated the carotid intima-media thickness (CIMT) as an indicator of macrovascular complications in a group of patients with GCK-MODY. Methods. Twenty-seven GCK mutation carriers and 24 controls recruited among their first-degree relatives were compared, all aging over 35 years. The CIMT was tested using a high-resolution B-mode carotid ultrasonography. Medical history, anthropometry, and biochemical blood workup were obtained. Results. The mean CIMT was 0.707 ± 0.215 mm (mean ± SD) in GCK mutation carriers and 0.690 ± 0.180 mm in control individuals. When adjusted for age, gender, and family status, the estimated mean difference in CIMT between the two groups increased to 0.049 mm (P = 0.19). No difference was detected for other characteristics, with the exception of fasting blood glucose (GCK-MODY 7.6 mmol/L ± 1.2 (136.4 mg/dL); controls 5.3 mmol/L ± 0.3 (95.4 mg/dL); P < 0.0001) and glycated hemoglobin HbA1c (GCK-MODY 6.9% ± 1.0%, 52 mmol/mol ± 10; controls 5.7% ± 0.4%, 39 mmol/mol ± 3; P < 0.0001). The frequency of myocardial infarction and ischemic stroke did not differ between groups. Conclusion. Our data indicate that the persistent hyperglycemia in GCK-MODY is associated with a low risk of developing diabetic macrovascular complications.